Enum aws_sdk_athena::model::ThrottleReason
source · #[non_exhaustive]
pub enum ThrottleReason {
ConcurrentQueryLimitExceeded,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against ThrottleReason
, it is important to ensure
your code is forward-compatible. That is, if a match arm handles a case for a
feature that is supported by the service but has not been represented as an enum
variant in a current version of SDK, your code should continue to work when you
upgrade SDK to a future version in which the enum does include a variant for that
feature.
Here is an example of how you can make a match expression forward-compatible:
# let throttlereason = unimplemented!();
match throttlereason {
ThrottleReason::ConcurrentQueryLimitExceeded => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when throttlereason
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant ThrottleReason::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
ThrottleReason::Unknown(UnknownVariantValue("NewFeature".to_owned()))
and calling as_str
on it yields "NewFeature"
.
This match expression is forward-compatible when executed with a newer
version of SDK where the variant ThrottleReason::NewFeature
is defined.
Specifically, when throttlereason
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on ThrottleReason::NewFeature
also yielding "NewFeature"
.
Explicitly matching on the Unknown
variant should
be avoided for two reasons:
- The inner data
UnknownVariantValue
is opaque, and no further information can be extracted. - It might inadvertently shadow other intended match arms.
The reason for the query throttling, for example, when it exceeds the concurrent query limit.
Variants (Non-exhaustive)§
This enum is marked as non-exhaustive
ConcurrentQueryLimitExceeded
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl AsRef<str> for ThrottleReason
impl AsRef<str> for ThrottleReason
source§impl Clone for ThrottleReason
impl Clone for ThrottleReason
source§fn clone(&self) -> ThrottleReason
fn clone(&self) -> ThrottleReason
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for ThrottleReason
impl Debug for ThrottleReason
source§impl From<&str> for ThrottleReason
impl From<&str> for ThrottleReason
source§impl FromStr for ThrottleReason
impl FromStr for ThrottleReason
source§impl Hash for ThrottleReason
impl Hash for ThrottleReason
source§impl Ord for ThrottleReason
impl Ord for ThrottleReason
source§fn cmp(&self, other: &ThrottleReason) -> Ordering
fn cmp(&self, other: &ThrottleReason) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere Self: Sized,
source§impl PartialEq<ThrottleReason> for ThrottleReason
impl PartialEq<ThrottleReason> for ThrottleReason
source§fn eq(&self, other: &ThrottleReason) -> bool
fn eq(&self, other: &ThrottleReason) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd<ThrottleReason> for ThrottleReason
impl PartialOrd<ThrottleReason> for ThrottleReason
source§fn partial_cmp(&self, other: &ThrottleReason) -> Option<Ordering>
fn partial_cmp(&self, other: &ThrottleReason) -> Option<Ordering>
1.0.0 · source§fn le(&self, other: &Rhs) -> bool
fn le(&self, other: &Rhs) -> bool
self
and other
) and is used by the <=
operator. Read moreimpl Eq for ThrottleReason
impl StructuralEq for ThrottleReason
impl StructuralPartialEq for ThrottleReason
Auto Trait Implementations§
impl RefUnwindSafe for ThrottleReason
impl Send for ThrottleReason
impl Sync for ThrottleReason
impl Unpin for ThrottleReason
impl UnwindSafe for ThrottleReason
Blanket Implementations§
source§impl<Q, K> Equivalent<K> for Qwhere
Q: Eq + ?Sized,
K: Borrow<Q> + ?Sized,
impl<Q, K> Equivalent<K> for Qwhere Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,
source§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.